Voter turnout was estimated at 7.8 percent of eligible voters by midday, including the about 282,000 votes already cast by mail, county officials said.

Orange County, by contrast, is seeing nearly double the turnout they had for their 2008 primaries - which still amounts to only 2.5 percent of eligible voters, not including the 250,000 mailed-in ballots.

Nevertheless, Secretary of State Debra Bowen said voting was going smoothly, with the state hotline getting only a 10th of the calls it received during the 2008 presidential election.

One Californian who has cast his vote is Governor Arnold Schwarzenegger. The governor, who supports eliminating party primaries, had to fill out a new ballot after he accidentally voted for two candidates in the Republican Senate primary.